天然火山岩粉混凝土在硫酸盐环境下的冻融耐久性试验研究  

Experimental study on freeze-thaw durability of natural volcanic rock powder concrete in sulfate environment

作　　者：程宁宁 王怀义 杨桂权 王深圳 CHENG Ningning;WANG Huaiyi;YANG Guiquan;WANG Shenzhen(College of Hydraulic and Civil Engineering of Xinjiang Agricultural University,Urumqi 830052,China;Xinjiang Institute of Water Resources and Hydropower Research,Urumqi 830049,China;Xinjiang Water Resources and Hydropower Materials Engineering Technology Research Center,Urumqi 830049,China)

机构地区：[1]新疆农业大学水利与土木工程学院,新疆乌鲁木齐830052 [2]新疆水利水电科学研究院,新疆乌鲁木齐830049 [3]新疆水利水电材料工程技术研究中心,新疆乌鲁木齐830049

出　　处：《新型建筑材料》2021年第5期47-51,共5页New Building Materials

基　　金：国家重点研发计划项目(2017YFC0405104);新疆自然科学基金面上项目(2019D01A74);新疆水工新材料测试研究评价共享平台项目(PT2022)。

摘　　要：采用快冻法研究了相同水胶比下,引气或不引气的纯水泥、掺加新疆和田地区天然火山岩粉或粉煤灰的混凝土在清水、1%Na2SO4、5%Na2SO4溶液中的耐久性变化规律,并结合低温冻结过程中硫酸盐溶液的冰点、完全冻结时长、体积膨胀率等低温性态进行探究。结果表明:冻结过程中硫酸盐溶液浓度越大,冰点越低、冰点时长越短、体积膨胀率越小;相同浓度溶液下,混凝土的冻融耐久性优劣依次为:粉煤灰>纯水泥≈火山岩粉;在硫酸盐冻前后混凝土的孔结构中,含气量、平均气泡直径、气泡间距系数都有所增大,气泡比表面积相对减小。In this paper,the durability change law of air-entrained and non-air-entrained pure cement concrete,natural volcanic powder concrete or fly ash concrete with same ratios of water-cementitious material,in clear water,1%Na2SO4 and 5%Na2SO4 solutions is studied by rapid freezing method,also the freezing point and complete freezing length and volume expansion rate of sulfate solution during low temperature freezing process are explored.The results show that,during the freezing process,the higher the concentration of sulfate solution,the lower the freezing point,the shorter the freezing point length,and the smaller the volume expansion rate.The freezing durability of concrete under the same concentration solution is:fly ash>pure cement≈volcanic rock powder.In the pore structure of concrete before and after sulfate freezing,the air content,average bubble diameter and bubble spacing coefficient increase,while the specific surface area of bubbles decreases.

关 键 词：火山岩粉混凝土 硫酸盐冻融 孔结构 低温性态 

分 类 号：TU528.041[建筑科学—建筑技术科学]